Automatic control mechanism for electric switches



Oct. 23,1923. 1,471,859

H. T. PATTON 1 AUTOMATIC CONTROL MECHANISM FOR ELECTRIC SWITCHES Filed Aug. 25 1920 2 Sheets-Sheet 1 I attozwaw Oct. 23 1923. I 1,471,859 H. T. PATTON AUTOMATIC CONTROL MECHANISM FOR ELECTRIC SWITCHES Filed Aug. 25 1920 2 SheetsSheet 2 a I 3; x a" g g3 N o x I? I Q, CE

A/ TIM/m attozvwga Patented Oct. 23, 1923.

UNITED STATES PATENT OFFICE.

HAL T. PATTON, OI CLEVELAND, OHIO, ASSIGNOR TO BISHOP & BABCOGK COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

AUTOMATIC CONTROL MECHANISM FOR ELECTRIO SWITCHES.

Application .flled August 25, 1920. Serialli'o. 405,821.

To all whom it may concern:

Be it known that I, HAL T. PA'I'ION, a citizen of the United States, and a resident of Cleveland, county of Guyahoga, and State of Ohio, have invented a new and useful Imrovement in Automatic Control Mechanism or Electric Switches, of which the following is a s cification, the princi 1e of the invention e'ing hereln explaine and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The present invention relates to an automatic control mechanism for electric switches, and is designed for the purpose of automatically controlling the operation of a switch or other power-controlling means upon the attainment of a predetermined pressure in various apparatus. The device may be used for controlling heating systems, or the pressure on individual water systems, or for controlling refrigerating or other apparatus. To the accomplishment of the,

foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description sets forth in detail certain I mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings Fig. 1 is a plan view partially in section of my improved device; Fig. 2 is a similar view showin certain modifications; and Fig. 3 is a p an view of my device shown more or less diagrammatically in connection with a system to be controlled thereby.

Referring now to Fig. 1, I .have shown a pressure-controlled memberin the form of a flexible corrugated metal bellows 1, which is suitably mounted upon a plate 2, which is in turn carried upon a'base plate or member 3. This flexible member 1 is provided with a head 4, to the closed end of which is attached a stem 5 carrying a cross member 6, on the ends of which are two substantially parallel arms 7 and 8, each of which is provided with a small roller 9. The other end of the flexible member 1 is attached to a head 10 which is engaged in an up-standing projection 11 on the base plate 2, this plate 10 being provided with an opening 12 therethrough connected crease in pressure willcause expansion of this member, while a decrease in pressure will allow for contraction.

As constructed in Fig. 1, the device is intended to'operate on subnormal pressures, and to maintain a given degree of vacuum in the reservoir, to which the pipe 13 leads In order to maintain the bellows member in an extended'position upon the normal degree of vacuum a coiled spring 141 is provided between the cross members 6 and a cap 16 encircling the stem 5 and mounted in a projection 17 on the base plate 2. Also an openendedtube 18 is attached to the plate 10 and extends longitudinally through the bellows 1 to prevent collapsing of the bellows or give the metal walls a permanent set. The head 10f the bellows will engage against the outer or open end of this tube 18 before injury to the bellows can occur.

The switch mechanism consists of a base plate 20 attached to the board 3, upon which are mounted binding posts 21 and 22 which are adapted to be engaged and electrically connected by means of switches consisting of a series of resilientplates 23 and 24. Each set of plates are connected together and mounted upon a longitudinally movable rod or switch member 25 by means of insulating blocks 26. In the position shown in Fig. 1, when the switches are closed the two-binding posts 21 are electrically connected, as are the two binding posts 22, and it will be understood that any desired number of switch members and binding posts may be used, depending upon whether a two-pole or three-pole or other switch is desired.

The rod 25 of the switch member is provided with two sets of bevel engaging faces 27 and 2 8, which are inclined in rections and adjoin each other. The rollers 9 on the arms 7 and 8 are pressed against such engaging surfaces by means of a spring 30 connecting these two arms.

In operation the normal position of the device is indicated in Fig. 1 for the controlof the vacuum system, and, as shown, the switches are closed and are held in such opposite dip p and 34 and the contacts.

closed position by means of the pressure of the rollers 9 against the beveled surfaces 28 on the rod 25, the pressure of these arms being maintained by the spring 30. As the pressure in the reservoir and within the bellows 1 falls, the bellows contracts, and in this way draws the stem '5 to the left, pulling the rollers 9 up the inclined surfaces 28 and tensioning the spring 30. The device may be so constructed that the rollers the points 31 where the o positely beveled engaging surfaces meet W en the pressure falls below the point which is to be maintained. When these rollers 9 are in engagement with the oppositely beveled faces 27 the tension which has been placed upon the spring 30 causes the arms to be brought toward each other and to press inwardly upon the surfaces 27, in this way forcing the switch member, 25 to the right, and breaking the connection between the binding. posts 21 and the posts 22. After the pressure in the bellows has v been restored to the desired point the rollers 9 are returned up the beveled surfaces 27 and snapped over onto the oppositely inclined surfaces 28, which reverses the pre: viously described action and closes the switches.

One important advantage secured by the action of the present mechanism is that the pressure of the switch members 23 and 24, and 33 and 34, against their contacts is maintained, and in fact somewhat, increased up to the point of the opening of the switch.

,This action is secured by the constantly increasing pressure of the rollers 9 against the beveled surfaces which they initially contact, and as these rollers are forced up the beveled surfaces the longitudinal pressure upon the switch rod 5 is increased up to the point where the rollers snap over, the point of juncture between the two oppositely inclined and beveled surfaces. Because of this construction there is no chance of arcing be tween the switch members 23 and 24 and 33 The spring 14 is always acting to force the stem 5 to the right and tends to restore the bellows to its normal condition and position as soon as the ressure within the bellows and the reservoir to be controlled have reached the predetermined amount. It is possible by the connection between the switch and the pressure control member to secure an instantaneous breaking of the electrical circuit and an instantaneous movement of the switch members, while preventing any movement at all during the initial movement of the/bellows and stem 5. In other words v the initial movement, up to the int at whichth'e break is desired to occur 1s either absorbed in lost motion as regards any movement of the switch 25, or is absorbed in tensioning the springBO, while the energy which is thus stored in the 9 will snap overs tion the bellows 1 is connected by means of the same stem 5 to a cros member 6, which carries the same arms 7 and 8, carrying the rollers 9, which operate against the same op- "positely beveled surfaces 27 and 28 on a. switch rod 25. The switch members proper 33 and 34,-are directed in the opposite di rection from those in the preceding figure, however, and the switch is opened by movement of the switch member to the left instead of to the right. A spring 35 is mounted between the bellowsl and the frame or base 2 and serves to return the bellows to its initial position after the pressure acting upon it has been restored to normal.

In this device, as the pressure is built up inthe bellows 1 it moves the stem 5 to the right, thus fdrcing the rollers 9 upwardly on the inclined surfaces 27 and tensioning the spring .30. As these rollers snap over the point 31 where the two beveled surfaces meet the stored pressure the spring 30 acts to draw the arms 7 and 8 together, and force the switch member 25 to the right, thus breaking the circuits throu h these switches.

In Fig. 3 I have shown t '0 device of Fig. 2 connected to a resure system to be controlled thereby. he conduit 13 leads to a reservoir 36, in which a given pressure is to be maintained. This reservoir 36 is r01 vided with a discharge conduit 37 an an inlet or charging conduit 38 the latter extending to a compressor 39, which is driven,

from a motor 40. The circuit through the motor is carried on the binding posts 21 and 22 on the switch. member and the breaking of this circuit through the movement of to be maintained at a given-point instead of a positive pressure.

Other modes of agplyingthe rinciple of my invention may loyed instead of the one explained, chug being made as re gards the mechanism herein disclosed, provided the means stated by an of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctl claim-.as my invention.

1. u an apparatus of the character do scribed, the combination of a support, a pressure or vacuum responsive device carried by support and encircling said reciprocating member, a spring surrounding said reciprocating member and interposed between two of said abutments, a second reciprocating member, a reversible switchcontact memher and a reversible cam block carried by said second reciprocating member, and lost motion means connecting said first reciprocatin member with said cam block.

2. in an apparatus of the character deciprocating mem scribed, the combination of a support, a pressure or vacuum responsive device carried by said suppgrt, a pair of aligned rers mounted on said support, lost motion means connecting saad members, a spring adapted for reversible association with one of said reciprocating members, a switch contact arm adapted to be reversibly associated with the other of said reciprocating members, and means associated with said lost motion means for abruptly actuating one of said reciprocating members.

Signed by me, this 20th day of July, 1920.

. HAL T PATTON. 

